Automatic choke heat tube

[Guest oakland]

The heat tube for 63 Riviera automatic choke has rusted and broken off. Is there any place I can fine a replacemnt heat Tube? Would I be better off converting the automatic choke to an electric one? If so, where can I purchase one? thanks.

[RivNut]

I replaced my automatic choke with the electric unit. I got if from Allstate Carburetor & Fuel Injection, Central Islip, NY. (631) 234-8327. I called them, told them what I needed and they were very knowledgeable about what I needed and what was in stock. At the same time, I also ordered a new stainless shim from them that goes between the carb and the intake. If this is how you decide to go, let me know and I'll give you some part numbers so you can wire your electric choke through your oil pressure sending unit. Unless the car is running and has oil pressure, there's no current to the electric choke. If your call stalls or you happen to have the key on and the cars not running, the choke is still operating. One nice thing about the electric choke is that you can fix the heat riser valve in the exhaust to a fully open position and let all the exhaust gas out during warm up instead of pushing it up toward the carburetor.

If you want to stick with the hot air choke, I would imagine that the guys at Allstate could help you as well.

Ed

[Guest oakland]

Thanks for the info. I contacted them and ordered the electric choke conversion. When it arrives, and I have trouble, I surely will ask for your help. I am not savy abut the heat riser valve. Will you please tell me where it is located and how I can block it open when I install the electric choke? Thank you.

[RivNut]

THe heat riser is a valve located at the base of the passenger side exhaust manifold. Threre's a butterfly valve in it that works on a spring. When the spring is cold, the butterfly closes in the exhaust and forces some hot air to the base of the carb; as exhaust heat warms the spring, it coils and opens the butterfly letting all of the exhaust gas out. As I look back at my original post, I may have been somewhat misleading about the purpose of this valve. It's used to heat the base of the carburetor during cold weather so that the fuel doesn't get ice crystals from the cold air in it when it's being vaporized on a very cold morning. If you don't drive your car on these extremely cold days, it's not necessary. On some models, the heat riser is a separate piece bolted between the manifold and the exhaust pipe; on others, it's built into the manifold. If you have a bolt on one and you don't need it, you can remove it. You may want to put a spacer in its place because you'll have to raise the exhaust pipe to compensate for the loss in length. Your pipes could make contact with the firewall or the floor pan if too much lenght is removed.

The small tube that runs through your manifold supplies the hot air to the choke. If you're installing an electric choke, you may still want the hot air on the base of the carb if you drive in a really cold environment. If you don't drive in that severe environment, you can wire the heat riser valve open (or remove it) and plug the holes on the carb flange so that no exhaust will reach the bottom of the carb. The carb may run a little rough until the engine warms up, but if you drive your car as I drive mine, it won't make that much difference. Let me know if you want some help with wiring suggestions for your electric choke.

[alex bonino]

I'd like to do the opposite. That is, go back to the stock Thermostatic choke. I currently have what looks to be a fairly new electtic someone put in.

Did you happen to keep your old thermostatic set up?

Anyone need a used electtic choke, free?

alex

ROA 11550

[RivNut]

Alex

I'll look around and see what I come up with. If I find it, I'll swap with you.

Ed

[Guest oakland]

I purchased an electric automatic choke, but have not had time to install it. When I do, I will contact RivNut for directions. I don't know how they are suppose to work, but am willing to try one due to the rusted heat tube and trouble I have with the present set up.

[alex bonino]

eBay comes through again. I have located a couple of old Carter carbs with the thermostatic choke intact, so hopefully that will do.

I plan on replacing the electric, so if anyone is interested in it, after I get the original assembly and install it, send me a PM.

thanks

Alex